Circuit breaker tie bar



1956 w. H. EDMUNDS CIRCUIT BREAKER TIE BAR 2 Sheets-Sheet 1 Filed Oct. 24, 1952 I u HANDLES ATTORNEYS Dec. 11, 1956 w. H. EDMUNDS CIRCUIT BREAKER TIE BAR 2 Sheets-Sheet 2 Filed Oct. 24, 1952 ATTORN EYS United States Patent CIRCUIT BREAKER TIE BAR William Harold Edmunds, Havel-town, Pa., assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa.

Application October 24, 1952, Serial No. 316,719

4 Claims. (Cl. 280-18) My present invention relates to circuit breakers and more particularly to a means for combining or interlocking two laterally adjacent panel board circuit breakers for simultaneous operation.

The type of panel board circuit breaker here referred to is that usually used in connection with the operation of home appliances and circuits. Such household circuit breakers are usually built in single pole sizes.

It is often necessary, however, to use two pole breakers for electric range and water heater circuits and for other circuits requiring either a higher voltage than that usually supplied to the remainder of the home appliances and circuits or a higher working load.

Since it is uneconomic to build multi-pole breakers for home use, it has become necessary to devise a means for combining single pole breakers so that essentially they will operate as a two pole breaker.

The present invention, therefore, relates to the specific means for tying together single pole breakers for simultaneous operation between the closed and open position.

The single pole circuit breaker of the type herein contemplated is so arranged that an opening spring will always provide the bias toward a tripping action when a latch is released.

This opening spring is, however, usually designed so that it will perform all of the desired operations with re spect to one circuit breaker when that circuit breaker trips. But when the circuit breaker trip operation is arranged so that this trip operation will be required to do more Work than merely trip the circuit breaker, the opening spring may not have sufficient energy to perform the operation.

Accordingly, in tying together circuit breakers in this manner, provision should be made so that the circuit breakers may be opened and closed simultaneously by a single manual operation, but also the connection or interlock must be so arranged that when one circuit breaker trips the tripping operation will not be required to perform the excess work and hence labor under the excess load of moving the other circuit breaker to the open position.

Consequently, the tie must be so arranged that while it will connect the circuit breakers for simultaneous closing and opening operations, the tripping of one circuit breaker will not affect the other circuit breaker.

At the same time, however, the tie must be so arranged that the resetting of the tripped circuit breaker to reengage its latch preliminary to closing the tripped circuit breaker will result in the opening of the other circuit breaker so that both will then thereafter be closed simultaneously.

Thus, the object of my invention is the provision of a novel circuit breaker tie mechanism arranged to permit simultaneous operation of circuit breakers between the closed and open position, individual tripping of either circuit breaker connected by the tie, and the opening of the untripped circuit breaker when the tripped circuit breaker is reset.

2,773,949 Patented Dec. 11, 1956 The foregoing and many other objects of my invention will become apparent in the following description and drawings in which:

Figure 1 is a plan view showing .two circuit breakers tied together by my novel tie device, one of the circuit breakers being shown in the tripped position.

Figure 2 is a side view of the circuit breakers of Figure 1 showing the manner of attachment of the tie device thereto.

Figure 3 is an exploded view of the tie bar, and associated parts.

Figure 4 is an elevation partially in section on line 44 of Figure 1 of the handle piece to which the tie bar is connected showing the contacts in closed position.

Figure 5 is a partial cross-sectional view similar to that of Figure 4 of a circuit breaker of the type to which my novel tie bar apparatus is connected with the contacts in the open position and the reset position shown in broken lines.

Referring first to Figure 4, the circuit breaker here shown is of well-known design. It is housed in a casing 10. Current passes from terminal 11 to the stationary contact 12, then to the movable contact 13, the pigtail 14, connector 15 to the opposite terminal 16.

Bimetal 17 is connected by contact 18 to the connector 15 and is also connected to the terminal 16. The latch 20 mounted on the bimetal member 17 engages the latching arm 21 which is independently rotatably mounted about the pin 60.

Contact arm 13a is pivotally connected at 27 to the extension of handle 23 below the pin 22. Tension spring 24 is connected at 25 to the contact arm 13a and at 26 to the latch arm 21. Tension spring 24 is an over-center spring holding the contact arm 13a in the open position in Figure 5.

When the handle 23 is moved to the left to closed position, pivot 27 of contact arm 13a moves to the other side of the center line 2625 as shown in Figure 8 and tension spring 24 then pulls the contact 13a over to cause contact 13 to engage contact 12.

When the bimetal strip 17 is heated sufficiently to pull latch 20 out from under the latch arm 21, then the spring 24 will pull down the latch arm 21 when the circuit breaker is in the closed position and simultaneously move the handle 23 to an intermediate position indicating that the circuit breaker has been tripped.

To reset the circuit breaker it will be necessary then to move the handle 23 back to the open position to reengage latch arm 21 with the latch 20. Thereafter the circuit breaker may be closed.

In Figure l I have shown two circuit breakers of the type of Figure 5 arranged side by side with their handles 23 adjacent to each other. A bracket 39 of the type shown in Figure 3 comprising a plate 40 and flange 42 is mounted on each handle 23.

The plate 40 of each bracket 39 is mounted on the outside surface of the handle 23 facing away from the other circuit breaker and is secured thereto by self-tapping screw 45 entering into an opening 46 in handle 23.

The flange 42 serves to position the bracket 39 against rotation. The bracket 39 extends out beyond the .opp-osite side of the handle to form extension 40a in which is placed the slot 40b.

The handle connector 50, shown also in Figure 3, is provided with a pair of ears 51, 51 adapted to engage the slots 4% in opposite handles as shown in Figures 1 and 2.

The shoulders 52 adjacent the ears 51 serve to position the handle connector 50.

Since panel board circuit breakers are set up by successive connection of circuit breakers side by side, the means of connection 01' the handle connector 50 will permit and in turn be permitted by the usual circuit breaker panel board erection method; that is, the first circuit breaker of Figure 1 is put into position with the bracket 39 on the handle. An ear 51 of the handle connector 50 is inserted therein, and the second circuit breaker with its bracket 39 is slid laterally toward the handle connector 50 until its bracket engages the opposite ear 51 of the handle connector 50.

The ears 51 and the slots or openings 40b in extensions 40a of bracket 39 are so dimensioned that the handle connector 50 may rock slightly with respect thereto.

Thus, the ordinary method of operating the two circuit breakers of Figures 1 and 2 together is to push on the handle connector 50 between the two circuit breakers, moving the circuit breakers either to the closed or to the open position.

The clearances of opening 40b around the cars 51 are such, however, that when either circuit breaker handle 23 is by itself snapped from the closed to the Open position or in the opposite direction, the other circuit breaker must follow and is also opened or closed as the case may be.

Since, however, during the tripping action the spring of either circuit breaker may not develop enough force to cause the other circuit breaker to open also, the clearance between opening 40b and ear 51 of the handle connector 50 is such as to permit the handle 23 to move from. the closed position to the intermediate trip position where the handle 23 is centered in the opening as shown in Figure 5 without moving the other circuit breaker from the closed to the open position.

When thereafter the tripped circuit breaker is moved to the open position to reset it, this additional movement will cause the other circuit breaker to move from the closed to the open position so that the circuit breaker must both be opened before they can be closed again and, as above pointed out, they must be closed and opened simultaneously.

By this means a simplified tie-in is provided for a pair of circuit breakers so that they will operate simultaneously but so that either circuit breaker may trip independently; while at the same time, the movement of the circuit breaker which has tripped to the open or reset position will cause the other circuit breaker to open also.

In the foregoing, I have described my invention solely in connection with specific illustrative embodiments thereof. Since many variations and modifications of my invention will now be obvious to those skilled in the art, I prefer to be bound not by the specific disclosures herein contained but only by the appended claims.

I claim:

1. A bracket assembly for inter-connecting the handles of a pair of adjacent circuit breakers; each of said handles being movable manually to a closed position and an open position; each of said handles being movable automatically to a position intermediate the closed and open positions; each of said handles being thereafter movable manually to a re-set position identical with the open position; said handles each being rota'tably movable in a single plane; said circuit breakers being arranged side by side so that the planes of movement of the handles are parallel; a bracket connected to each of said handles; each of said brackets extending beyond its respective said handle and having a slot therein; a rigid handle connecting bar having opposite ears engaged in the slots of said handle brackets; a clearance between the ears and the slots permitting one of said handles to move to the automatic trip position while the other of said handles remains at said closed position; the movement of said tripped handle to said re-set position causing the other said handle to move from said closed to said open position, the manual movement of either of said handles from said closed to said open position and from said open to said closed position causing the other handle to move correspondingly.

2. A bracket assembly for inter-connecting the handles of a pair of adjacent circuit breakers; each of said handles being movable manually to a closed position and an open position; each of said handles being movable automatically to a position intermediate said closed and said open positions; each of said handles being thereafter movable manually to a re-set position identical with said open position; said handles each being rotatably movable in a single plane; said circuit breakers being arranged side by side so that the planes of movement of said handles are parallel; a bracket connected to each of said handles; each of said brackets extending beyond its respective said handle and having a slot therein; a rigid handle connecting bar having opposite ears engaged in said slots of said handle brackets; the manual movement of either of said handles from said closed to said open position and from said open to said closed position causing the other of said handles to move correspondingly; said handles being operable simultaneously by said handle connecting bar.

3. A bracket assembly for inter-connecting the pivoted handles of adjacent circuit breakers, said assembly comprising a pair of brackets each connectable to a handle; each bracket having a fiat plate with an opening; said flat plate having an extension with a slot; each bracket also having a flange at the end opposite to the slot and normal to the plate; a rigid handle connecting bar having opposite ears insertable in said slots.

4. A bracket assembly for inter-connecting the handles of adjacent circuit breakers, said assembly comprising a pair of brackets each connectable to a rotatable handle; each bracket having a fiat plate with an opening; said flat plate having an extension with a slot; each bracket also having a flange at the end opposite to the slot and normal to the plate; a rigid handle connecting bar having opposite ears insertable in said slots, said ears having clearance in the slots permitting the handle connecting bar to have some rotative movement in the slots.

References Cited in the file of this patent UNITED STATES PATENTS Re. 22,218 Von Hoorn Nov. 3, 1942 2,096,545 Jackson Oct. 19, 1937 2,096,548 Jackson Oct. 19, 1937 2,099,585 Von Hoorn Nov. 16, 1937 2,209,353 Sachs July 30, 1940 2,277,645 Johnson Mar. 24, 1942 

